@Aditya_Srinivas - If all your 1000 Pdf invoices follows the same pattern, then
- Read PDF activity , using Preserve format true and output to Stringvariable.
- Input the stringvariable to Matches activity and build Regex pattern
- Write the output
It will be different for every cases. if you could you share some sample text from the read pdf activity , we can help with Regex.
You can refer this post.